It is often desirable for electronic devices to transmit data, transfer power, or otherwise communicate one with another. For example, a microprocessor is often configured to transmit data to and receive data from a peripheral device such as a flash memory device.
Reliable communication is especially important in medical devices, where miscommunication may result in device malfunction and harm to a patient. For example, many implantable medical devices, such as implantable stimulators, are configured to transmit status updates to and receive operational instructions and power from one or more external devices. Without accurate communication, these implantable medical devices could cease to function properly.
An exemplary implantable medical device is an implantable cochlear stimulator (ICS), which may be used to treat sensorineural hearing loss. An ICS seeks to bypass the hair cells in the cochlea, which are essential to hearing but which may not be functioning properly, by presenting electrical stimulation directly to the auditory nerve fibers. This leads to the perception of sound in the brain and at least partial restoration of hearing function.
A typical ICS is intended to remain permanently in the body of a patient once it is implanted. For this reason, a behind-the-ear (BTE) signal processor may be positioned behind the ear and used to support the ICS by transmitting various stimulation parameters to the ICS, receiving status data from the ICS, and/or providing power to the ICS.
It is often desirable to modify the stimulation parameters that are transmitted to an ICS by a BTE signal processor or otherwise program the BTE signal processor. To this end, a clinician's programming interface (CPI) is often used. A CPI is a device that allows a programming device (e.g., a personal computer or the like) to interface with a BTE processor. The CPI is typically connected to a BTE with a programming cable.
The same CPI is often used to facilitate the programming of many different types of BTE processors. However, the CPI and each BTE processor may be configured to operate using different supply voltages. For example, a typical CPI operates at 3.0 volts while some BTE processors operate at 2.0 volts and others at 2.7 volts. However, optimal communication between two devices occurs when both devices are operating at the same voltage level. Hence, the difference in supply voltages between the CPI and the BTE processors makes it difficult for accurate communication to occur therebetween.
The above example is typical of many different instances where communication between two devices is sub-optimal or impossible due to differences in supply voltage levels. Various arrangements are currently used to facilitate communication between devices having different having different supply voltage levels. However, many of these arrangements have a number of drawbacks.
For example, to facilitate communication between a CPI and a BTE processor, the programming cable that couples the two devices may include circuitry that converts one supply voltage level to the other. However, if the same CPI is used to program multiple BTE processors each operating at different voltage levels, this approach would require different programming cables to be used for each BTE processor. The use of multiple programming cables is often undesirable because of cost, complexity, and the potential for confusion.